Conserving Soil in Organic Crops

Soil is the production base of all agricultural systems. Soil conservation is one of the pillars of sustainability. Soil quality has deteriorated due to wind and water erosion, as well as farming practices that reduce organic matter content. Soil conservation promotes practices that stop the decline and, over time, improve soil quality. In general maintaining soil cover, living plant roots and limiting soil disturbance are the best ways to limit erosion.

Conservation practices generally reduce wind erosion, reduce rate and amount of lateral water movement in fields, and increase soil organic matter levels. There is not one way of conserving soil that is well suited to all situations, due to differences in soil type, topography, type of farming operation and climate.

In organic crop production, the challenge increases, because conservation practices that involve pesticides are not an option. In every case, it is generally more effective to use a number of conservation strategies. For example, rather than plant a large number of shelterbelts on a particular field, it may be better to plant a lesser number and reduce tillage operations or include green manure more often to keep soil surface covered. The challenge is determining which conservation practices are best adapted to each farm.

Crop Residues

Crop residues include roots, chaff, stems and leaves are left after a crop is harvested. Crop residues are the prime source of organic matter replenishment. These residues improve several soil properties, such as water infiltration, water storage and particle aggregation. Crop residues also contain nutrients, including nitrogen, phosphorus, potassium, sulphur and micronutrients. Moisture conservation is important to soil conservation because the additional moisture will improve crop growth the following year.

The amount of residue produced and the rate of decay vary among crops. The combination of these two factors determines the quality of residue in relation to its value for soil conservation.

Let’s Save Our Soils

We take soil for granted, but the thin layer of top soil on the planet is the source for almost all our food. Take it away and you can imagine the result! And it is being taken away in enormous quantities. Bad agricultural practices lead to massive soil erosion – India alone loses 5300 million tons of soil a year – and chemical-based farming poisons what’s left.